Home INTRODUCTION OVERVIEW SITE NAVIGATION INTERLOCKING MACHINES
INTERLOCKING TERMS & miscellaneous notes

CTC- Centralized traffic control

GRS-General Railway Signalling

Home Signal-signals at the limits of an interlocking

IS&F-International Saxby and Farmer

NX Machine- Called an "Entrance-Exit" machine.Operator
pushed buttons at point of trains entrance and exit and the machine calculated the best route for the movement.

Plant-slang for area covering interlocking

FP lock- facing point lock,movement of two levers was required to re position a turnout

S8 machine-electrical add ons to an existing mechanical machine. photo example...S 8 machine

SF Saxby and Farmer

USS-Union Switch and Signal Co.

Pennsylvania primarily used USS equipment
New York Central primarily used GRS

Due to Union rules PRR train dispatchers could NOT line switches.


RAILROAD ABBREVIATIONS
ATSF  Santa Fe
B&O  Baltimore and Ohio
C&IL Chicago Indianapolis and Louisville (Monon)
C&O  Chesapeake and Ohio
DL&W  Delaware Lackawanna and Western
GM&O  Gulf Mobile and Ohio
GR&I  Grand Rapids and Indiana part of the PRR system
IC  Illinois Central
IURY  Indianapolis Union Railway (Belt Railroad)
L&N  Louisville and Nashville
MILW  CMStP&P(Milwaukee)
NKP New York, Chicago and St. Louis (Nickel Plate)
N&W  Norfolk and Western
P&E  Peoria and Eastern owned an operated by the New York Central
PRR  Pennsylvania Railroad
NYC  New York Central
T&OC  Toledo Ohio Central part of NYC System
WAB  Wabash



 



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INTRODUCTION
OVERVIEW
SITE NAVIGATION
INTERLOCKING MACHINES
TOWER NAMES AND CALL LETTERS
SUPPLEMENTAL TOWER MATERIAL
STATES  A-W and  CANADA
ILLINOIS
INDIANA
NEW JERSEY
NEW YORK
OHIO
PENNSYLVANIA
ABBREVIATIONS & GLOSSARY
LINKS
LOCK & BLOCK TOWERS
MY FIRST TOWER ASSIGNMENT
APRIL UPDATES
MAY UPDATES
JUNE UPDATES
APRIL 2022 UPDATES
OPERATORS HALL OF FAME
TRANSIT & ELECTRIC LINE TOWERS
RAILROAD MAPS
RESTORATIONS
TALES FROM THE TOWER
UNKNOWNS
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